The present invention relates to a improved thermo-pneumatic unit and apparatus for thermal treatment of moving flat animal hides, and more particularly relates to a improvement in arrangements for processing a plurality of mutually spaced flat animal hides such as cowhides along a prescribed travelling path under application of drying by means of forced entry of heated air flow into spaces between the successive flat animal hides.
Taking the drying process of cowhides as a typical example, a plurality of panels on which cowhides are disposed in a flat spreaded disposition travel along a prescribed path longitudinally through an elongated drying chamber. The panels are suspended from overhanging guide rails in a mutually spaced relationship to each other with their planes extending perpendicular to the direction of travel. Heat is applied to the moving cowhides by a floor heater. In the conventional arrangement, a number of axial-flow fans or parallel air flow blowers are arranged on one lateral side of and along the travelling path in order to generate flow of the air in the spaces between the successive panels, thereby evening the thermal effect over the entire cowhide. Especially in practice, a cowhide is generally comprised of a number of local portions of initially different moisture content. Consequently, properly rated heating at one local portion of the cowhide often tends to cause undesirable overheating and/or insufficient heating at other local portions of the cowhide. Such locally uneven thermal treatment on the cowhide leads to an inevitable degradation in quality of the cowhide after the treatment, and a substantial loss in thermal energy. That is, in the case of animal hides such as cowhides having geographical variance in moisture content or thermal capacity, different local portions of the animal hide require application of differently rated thermal treatment even using a common supply source of the heated air flow.